About 70% of the premature failure of various electr […]
About 70% of the premature failure of various electromechanical products is caused by wear and corrosion, both of which are closely related to the surface state (physical, chemical and stress states, etc.) of the material. Therefore, the key to improving the performance of such materials is to improve their surface properties.
With the development of science and technology, the surface performance of the material requirements are getting higher and higher. In recent decades, the rise of a variety of vapor deposition technology, surface engineering technology research and application have made rapid development. These technologies not only meet the requirements of mechanical properties, such as wear, friction and corrosion resistance, but also in the field of electromagnetic, optical, optoelectronics, thermal, superconductivity and biology and surface related functional materials to show their talents. Surface engineering not only low-cost metal materials in terms of performance and efficiency to play a greater advantage, and has become the development of new coating and film materials, an important means, has great potential applications.
With the improvement of the level of machining industry, the tool put forward new requirements. In addition to improving the service life also requires reduction of cutting pollution, as far as possible the use of dry cutting. When the cutting fluid can not be completely eliminated, it is possible to reduce the cost of the recycle recovery as much as possible.
The diversity of cutting tools and the use of the working state of the characteristics of the choice of the choice of different tool plating. Turning and drilling different, milling cutter should also consider the characteristics of its intermittent impact. Early development of the coating to wear as the main focus to improve the hardness as the main indicator. Titanium nitride as the representative of such coatings have a high coefficient of friction (0.4 ~ 0.6), continuous friction between the workpiece and the workpiece will produce a lot of heat. In order to avoid deformation of the tool overheating affect the processing accuracy and extend its service life, usually use cutting fluid.
To solve the problem of reducing or eliminating the cutting fluid, the tool coating should not only make the tool long life, and should have self-lubricating function. The presence of diamond-like coatings (DLC) shows an advantage in the machining of certain materials (Al, Ti and its composites), but after years of research it has shown that the diamond-like coatings have high internal stresses and poor thermal stability And the catalytic effect between the black metal SP3 structure to SP2, and other three shortcomings, it is currently only applicable to the processing of non-ferrous metals, thus limiting its further processing in the machine. However, recent studies have shown that the hardness of the diamond-like coating (also known as graphite-like coating), which is dominated by SP2 structure, can reach 20 ~ 40 GPa, but there is no problem with the ferrous metal as the catalyst effect. Low and good resistance to moisture, cutting can be used when the coolant can also be used for dry cutting, its life than the non-coated knife has doubled to improve the processing of steel material is not a problem, which caused the coating company, tool manufacturers Big interest. In time, this new type of diamond-like coating will be widely used in the cutting field.